公开(公告)号：US5790006A

公开(公告)日：1998-08-04

申请号：US754916

申请日：1996-11-22

申请人： Manlio G. Abele ,  Henry Rusinek ,  Jens Jensen

发明人： Manlio G. Abele ,  Henry Rusinek ,  Jens Jensen

IPC分类号： A61B5/055 ,  G01R33/38 ,  G01R33/383 ,  H01F7/02

CPC分类号： G01R33/3808 ,  G01R33/383 ,  H01F7/0278

摘要： A magnetic structure generating a substantially uniform magnetic field within a region of interest comprising at least one pair of magnetic wedges of substantially identical shape arranged symmetrically about a first axis and abutting one another along a common edge. Each magnetic wedge has a first side and a second side which terminate at the common edge. The first wedge of each pair is positioned to define a first angle between the first side and the first axis and a second angle between the second side and the first axis, and is uniformly magnetized in a direction relative to a second axis (perpendicular to the first axis) which is a function of the sum of the first and second angles. The second wedge of each pair is magnetized such that the absolute values of components of the magnetization along the first and second axes are equal to components of the magnetization of the first wedge along the first and second axes, respectively, and one of the magnetization components of the second wedge is opposite to the respective magnetization component of the first wedge. The region of interest containing the substantially uniform field is between the first sides of the pair of wedges, the second sides of the pair of wedges, or both. To minimize or eliminate the surface charge density along the third side of each wedge, the third side of each wedge is preferably parallel to the direction in which the wedge is magnetized.

摘要翻译： 在感兴趣区域内产生基本上均匀的磁场的磁性结构包括至少一对基本上相同的形状的一对磁楔，所述磁楔基本相同的形状围绕第一轴对称地布置并且沿共同边缘彼此邻接。 每个磁楔具有终止于公共边缘的第一侧和第二侧。 每对的第一楔定位成在第一侧和第一轴之间限定第一角度，并且在第二侧与第一轴之间形成第二角度，并且在相对于第二轴线（垂直于第二轴线）的方向上均匀地磁化 第一轴），其是第一和第二角度之和的函数。 每对的第二楔被磁化，使得沿着第一和第二轴的磁化的分量的绝对值分别等于第一楔形物沿着第一和第二轴的磁化的分量，并且磁化分量之一 的第二楔形件与第一楔形件的各自的磁化分量相反。 包含基本上均匀的场的感兴趣区域位于该对楔形物的第一侧，该楔形物的第二侧或两者之间。 为了最小化或消除沿着每个楔形件的第三侧的表面电荷密度，每个楔形件的第三侧优选地平行于楔形物被磁化的方向。

公开(公告)号：US5495222A

公开(公告)日：1996-02-27

申请号：US406340

申请日：1995-03-13

申请人： Manlio G. Abele ,  Henry Rusinek ,  Jens Jensen

发明人： Manlio G. Abele ,  Henry Rusinek ,  Jens Jensen

IPC分类号： G01R33/383 ,  A61B5/055 ,  G01R33/38 ,  G01R33/3873 ,  G01V3/00 ,  G01V3/14 ,  G03G21/00 ,  H01F7/02

CPC分类号： G01R33/3873 ,  G01R33/3806 ,  G01R33/383

摘要： A hybrid permanent magnet structure for providing a uniform magnetic field within a region of interest while allowing access via open ends by a patient for NMR scanning and by a surgeon to the patient via a large opening at the top. The magnet structure comprises nested inner and outer magnetic structures separated by ferromagnetic material and surrounded by a ferromagnetic yoke. The inner magnetic sections comprise end blocks of triangular cross-section, and the outer magnetic sections comprise end blocks of trapezoidal cross-section. Field distortion compensating means is provided by a primary filter structure to the ferromagnetic material and by magnetic insertions or a secondary filter structure.

摘要翻译： 一种混合永磁体结构，用于在感兴趣的区域内提供均匀的磁场，同时允许通过开放端通过患者进行NMR扫描，以及外科医生通过顶部的大开口到患者。 磁体结构包括由铁磁材料分离并被铁磁轭环绕的嵌套的内部和外部磁性结构。 内部磁性部分包括具有三角形横截面的端部块，并且外部磁性部分包括具有梯形横截面的端部块。 场失真补偿装置由初级过滤器结构提供给铁磁材料，并通过磁性插入或次级过滤器结构提供。

公开(公告)号：US5475355A

公开(公告)日：1995-12-12

申请号：US228291

申请日：1994-04-15

申请人： Manlio G. Abele ,  Henry Rusinek ,  Jens Jensen

发明人： Manlio G. Abele ,  Henry Rusinek ,  Jens Jensen

IPC分类号： G01V3/14 ,  A61B5/055 ,  G01R33/38 ,  G01R33/383 ,  G01R33/3873 ,  H01F7/02 ,  G01V3/00 ,  G03G21/00

CPC分类号： G01R33/3873 ,  G01R33/3806 ,  G01R33/383

摘要： A technique is provided for improving the homogeneity of the magnetic field within a cavity disposed inside a magnetic structure that has an opening to permit convenient access to an imaging region. The technique is based upon the step of inserting layers of magnetized material between plates of high magnetic permeability material. The layers are inserted at the boundary of the cavity. The technique includes the step of (1) computing the surface charges on the plates as used to derive the distribution of the magnetostatic potential, (2) analyzing the uniformity of the magnetic field within the imaging region as effected by the opening in the magnetic structure by expanding the magnetostatic potential in a spatial harmonic series, and (3) determining the geometry and the composition of the inserted layers based on the successive elimination of increasing orders of spatial harmonics in the potential expansion within the imaging region. This invention also includes the structure resulting from carrying out the technique of the invention.

摘要翻译： 提供了一种技术，用于改善设置在具有开口以允许方便地进入成像区域的开口的磁性结构内的空腔内的磁场的均匀性。 该技术基于在高磁导率材料的板之间插入磁化材料层的步骤。 这些层被插入空腔的边界。 该技术包括以下步骤：（1）计算用于导出静磁电位分布的板上的表面电荷，（2）通过磁性结构中的开口来实现分析成像区域内的磁场的均匀性 通过扩展空间谐波序列中的静磁电位，以及（3）基于在成像区域内的电势扩展中连续消除空间谐波的增加次数来确定插入层的几何形状和组成。 本发明还包括由实施本发明技术而得到的结构。

公开(公告)号：US06265959B1

公开(公告)日：2001-07-24

申请号：US09069389

申请日：1998-04-29

申请人： Manlio G. Abele ,  Jens Jensen ,  Henry Rusinek

发明人： Manlio G. Abele ,  Jens Jensen ,  Henry Rusinek

IPC分类号： H01F500

CPC分类号： H01F7/0278 ,  G01R33/3806 ,  G01R33/383

摘要： A magnetic structure generating a uniform magnetic field within a region of interest using permanently magnetized prism-shaped blocks of magnetic material positioned around a cavity and which constitute the predominant generator of the uniform magnetic field in the desired region of interest. The magnetic structure has a plane surface comprising a high permeability ferromagnetic member interfacing with a first side of the cavity and forming a single pole piece of the magnetic structure. The magnetic structure produces within the cavity adjacent the single pole piece the uniform magnetic field and collects the magnetic flux flowing through the single pole piece and through the cavity, with the region of interest being located adjacent the single pole piece. A second side of the cavity generally opposite to the first side is open to a surrounding medium and forms an interface with the surrounding medium but not with a magnetic member. The magnetic structure is designed assuming a hypothetical high permeability membrane parallel to the single pole piece and located where the open second side of the cavity will be made, the high permeability membrane forming an equipotential surface at the interface with the surrounding medium. This minimizes the fringe field generated in the surrounding medium when the second side of the cavity is opened.

摘要翻译： 一种磁性结构，其在感兴趣的区域内使用位于空腔周围的永久磁化的棱柱形磁性材料块产生均匀磁场，并且构成所需感兴趣区域中均匀磁场的主要发生器。 磁性结构具有包括与空腔的第一侧接合的高磁导率铁磁构件的平面，并形成磁结构的单极片。 磁性结构在与单极片相邻的腔内产生均匀的磁场，并收集流过单极片并通过腔的磁通量，感兴趣区域位于单极片附近。 大致与第一侧相对的空腔的第二侧对周围的介质是开放的，并与周围的介质形成界面而不与磁性构件形成界面。 磁性结构被设计为假设与单极片平行的假想高渗透膜，并且位于将形成空腔的开口第二侧的位置，高渗透膜在与周围介质的界面处形成等电位面。 当空腔的第二侧被打开时，这最小化周围介质中产生的边缘场。

公开(公告)号：US06225887B1

公开(公告)日：2001-05-01

申请号：US08885095

申请日：1997-06-30

申请人： Jens Jensen ,  Manlio G. Abele ,  Henry Rusinek

发明人： Jens Jensen ,  Manlio G. Abele ,  Henry Rusinek

IPC分类号： H01F702

CPC分类号： G01R33/3808 ,  G01R33/383 ,  H01F7/0278

摘要： A magnetic structure generating a substantially uniform magnetic field within a region of interest using permanently magnetized wedge-shaped blocks of magnetic material. In a preferred embodiment, the permanently magnetized wedge-shaped blocks are provided in pairs positioned on opposite sides of the x z plane of an arbitrary x,y,z coordinate system, and each of the blocks are magnetized in certain directions. The uniform field is created in the vicinity of the z axis. In another embodiment, the parts of the structure below the x-axis are replaced by a high-permeability, soft magnetic plate to form a so-called mirror system. In still another embodiment, permanently magnetized blocks positioned outside of the wedge-shaped blocks are employed as the main compensation means for field distortions arising from the practical need to truncate the wedge-shaped blocks to a practical size. An important application for the magnetic structure of the invention is MRI, as it can be configured as an open structure accessible to medical intervention during the MRI.

摘要翻译： 一种使用永久磁化的楔形磁性材料块在感兴趣区域内产生基本上均匀的磁场的磁性结构。 在优选实施例中，永久磁化的楔形块成对地设置成位于任意x，y，z坐标系的x z平面的相对侧上，并且每个块在某些方向被磁化。 在z轴附近产生均匀场。 在另一个实施例中，x轴下方的结构部分由高磁导率软磁性板替代，形成所谓的反射镜系统。 在另一个实施例中，位于楔形块之外的永久磁化块被用作由实际需要将楔形块截截到实际尺寸而产生的场失真的主要补偿装置。 本发明的磁性结构的重要应用是MRI，因为其可以被配置为在MRI期间医学干预可接近的开放结构。

公开(公告)号：US5798680A

公开(公告)日：1998-08-25

申请号：US613756

申请日：1996-02-26

申请人： Manlio G. Abele ,  Henry Rusinek ,  Jens Jensen

发明人： Manlio G. Abele ,  Henry Rusinek ,  Jens Jensen

IPC分类号： A61B5/055 ,  G01R33/38 ,  G01R33/383 ,  H01F7/02

CPC分类号： H01F7/0278 ,  G01R33/3806 ,  G01R33/383

摘要： Strapped open magnetic structure, particularly useful in nuclear magnetic resonance imaging applications, which provides a substantially uniform magnetic field within a region of interest while allowing access by a surgeon to a patient via an opening at the top of the magnetic structure. The magnetic structure comprises nested inner and outer magnetic structures separated by ferromagnetic material or pole pieces and surrounded by a ferromagnetic yoke. The structure contains one or more thin layers or straps of high magnetic permeability material aligned substantially along equipotential surface(s) of an associated closed magnetic structure of ideal properties. Structures and techniques are also provided for replacing thick, heavy blocks of ferromagnetic material with thin straps and for extending the magnetostatic potential of a component in a magnetic structure by connecting a thin strap thereto and embedding the strap in the magnetic structure along an equipotential surface of the magnetic field generated by the magnetic structure.

摘要翻译： 带状的开放式磁结构，特别适用于核磁共振成像应用，其在感兴趣区域内提供基本均匀的磁场，同时允许外科医生通过磁性结构顶部的开口进入患者。 磁性结构包括由铁磁材料或极片分离并被铁磁轭环绕的嵌套的内部和外部磁性结构。 该结构包含一个或多个基本上沿着理想特性的关联闭合磁性结构的等电位表面排列的薄磁层或高磁导率材料带。 还提供了结构和技术，用于用薄带替代厚厚的强磁性材料块，并且通过将薄带连接到其上并通过将薄带连接到磁性结构中并将带嵌入磁性结构中，从而将组件的静磁电位延伸到磁性结构中 由磁性结构产生的磁场。

公开(公告)号：US5055812A

公开(公告)日：1991-10-08

申请号：US587285

申请日：1990-09-24

申请人： Manlio G. Abele ,  Ramesh Chandra ,  Henry Rusinek ,  Ernest Potenziani, II ,  Herbert A. Leupold

发明人： Manlio G. Abele ,  Ramesh Chandra ,  Henry Rusinek ,  Ernest Potenziani, II ,  Herbert A. Leupold

IPC分类号： G01R33/383 ,  G01R33/3873 ,  H01F7/02

CPC分类号： H01F7/0278 ,  G01R33/383 ,  G01R33/3873

摘要： A permanent magnet structure comprising a longitudinally extending flux sce fabricated of magnetically rigid material. The flux source comprises a central cavity with a magnetic field being produced therein. Magnetic dipoles having predetermined magnitude and orientation for compensating nonuniformities in the magnetic field are symmetrically located within the plane of the flux source.

摘要翻译： 一种永磁体结构，包括由磁性刚性材料制成的纵向延伸的磁通源。 磁通源包括其中产生磁场的中心腔。 具有用于补偿磁场中的不均匀性的预定幅度和取向的磁偶极子对称地位于通量源的平面内。

公开(公告)号：US5412365A

公开(公告)日：1995-05-02

申请号：US185726

申请日：1994-01-24

申请人： Manlio G. Abele ,  Henry Rusinek

发明人： Manlio G. Abele ,  Henry Rusinek

IPC分类号： A61B5/055 ,  G01R33/383 ,  H01F7/02

CPC分类号： G01R33/383 ,  H01F7/0273 ,  H01F7/0278

摘要： A high field strength permanent magnet has a plurality of layers, with at least two of the layers being formed of materials of different remanence. The remanence of the material of each layer is no greater than that of the layers thereunder, and is preferably less than the remanence of all underlying layers.The inner layer may be formed of a magnetic structure in which all or part of a basic yoke has been replaced by a shunt of active material. Such a shunt may alternatively be employed in a single layer magnetic structure.

摘要翻译： 高场强永磁体具有多个层，其中至少两个层由不同的剩磁材料形成。 每个层的材料的剩余量不大于其下面的层的剩余，并且优选地小于所有下层的剩磁。 内层可以由磁性结构形成，其中基本磁轭的全部或部分已被活性材料的分路代替。 这种分路可以替代地用于单层磁结构中。

公开(公告)号：US5278534A

公开(公告)日：1994-01-11

申请号：US938849

申请日：1992-09-01

申请人： Manlio G. Abele ,  Henry Rusinek

发明人： Manlio G. Abele ,  Henry Rusinek

IPC分类号： G01R33/383 ,  H01F7/02

CPC分类号： H01F7/0278 ,  G01R33/383

摘要： A magnetic structure defining a cavity includes a first member of high-permeability material having a flat surface defining a first wall of the cavity, and a member of permanent magnetic material spaced from the flat surface and producing a uniform magnetic field in the cavity. The permanent magnetic material member may have two or more layers, with the layers outward of the cavity being of a material having a remanence that is no greater than the adjacent inner layers.

摘要翻译： 限定空腔的磁性结构包括具有限定空腔的第一壁的平坦表面的高导磁率材料的第一构件和与平坦表面间隔开并在空腔中产生均匀磁场的永久磁性材料的构件。 永久磁性材料构件可以具有两层或更多层，空腔外侧的层是具有不大于相邻内层的剩磁的材料。

公开(公告)号：US5428333A

公开(公告)日：1995-06-27

申请号：US007523

申请日：1993-01-22

申请人： Manlio G. Abele ,  Henry Rusinek

发明人： Manlio G. Abele ,  Henry Rusinek

IPC分类号： H01F27/34 ,  G01R33/383 ,  G01R33/3873 ,  H01F7/02

CPC分类号： G01R33/383 ,  G01R33/3873 ,  H01F7/0278

摘要： A magnetic structure is provided having a pair of spaced apart magnetized elements having surfaces in a common plane that defines a wall of a cavity. The space between the first and second magnetized elements is formed with at least one slit extending perpendicularly to the common plane. In order to compensate for field distortion in the cavity, a magnetized element is provided in at least one of the slits, the material in the slit having a remanence that is different from the remanences of the spaced apart magnetized elements that define the structure. In modifications of the invention, the field distortion is compensated by including at least one component in the cavity that has a high magnetic permeability. This component, has a variable thickness. It may be formed of a single component, or of a plurality of plates. In a still further embodiment, for a yokeless magnetic structure, field distortion compensation is effected by positioning magnetized elements outside of the magnetic structure. In a method for compensating for field distortion in a magnetic structure that defines a cavity, the magnetic field on a surface is measured to produce a map of the field on the surface. A plurality of points on the surface are projected to corresponding points on a second surface. A dipole is applied at each such point on the second surface that cancels perturbations of the magnetic field of the magnetic structure at the respective first point.

摘要翻译： 提供一种磁性结构，其具有一对间隔开的磁化元件，该元件具有限定空腔壁的公共平面中的表面。 第一和第二磁化元件之间的空间形成有至少一个垂直于公共平面延伸的狭缝。 为了补偿空腔中的场失真，在至少一个狭缝中提供磁化元件，狭缝中的材料具有与限定结构的间隔开的磁化元件的剩磁性不同的剩磁。 在本发明的修改中，通过在空腔中包括具有高磁导率的至少一个分量来补偿场失真。 该组件具有可变的厚度。 它可以由单个部件或多个板形成。 在另一实施例中，对于无轭磁结构，通过将磁化元件定位在磁结构外部来实现场失真补偿。 在用于补偿限定空腔的磁性结构中的场失真的方法中，测量表面上的磁场以产生表面上的场的图。 表面上的多个点被投影到第二表面上的相应点。 偶极子被施加在第二表面上的每个这样的点处，以抵消在相应的第一点处的磁性结构的磁场的扰动。